Optimum Hole Sizes for Common Birdhouse Nesting Species
Birds have their own minds and don't always follow the rules! But below is a general guide that might be helpful. The birds in our yard seem to choose their houses based on many different factors including size, hole size, and location. Hopefully this helps!
Different individuals of the same bird species may vary slightly in size, but that variation is so small that birdhouse hole sizes can be made to standard dimensions without difficulty. These basic entrance sizes can help attract just the types of birds you want to become backyard residents.
- American Kestrel - 3 inches (7.6 cm)
- Ash-Throated Flycatcher - 1 1/2 inches (3.8 cm)
- Barn Owl - 6 inches (15.2 cm)
- Black-Capped Chickadee - 1 1/8 inches (2.85 cm)
- Carolina Chickadee - 1 1/8 inches (2.85 cm)
- Carolina Wren - 1 1/2 inches (3.8 cm)
- Downy Woodpecker - 1 1/4 inches (3.2 cm)
- Eastern Bluebird - 1 1/2 inches (3.8 cm)
- Eastern Screech-Owl - 3 inches (7.6 cm)
- House Finch - 2 inches (5.1 cm)
- House Wren - 1 1/4 inches (3.2 cm)
- Northern Flicker - 2 1/2 inches (6.35 cm)
- Prothonotary Warbler - 1 1/8 inches (2.85 cm)
- Purple Martin - 2 1/2 inches (6.35 cm)
- Tree Swallow - 1 3/8 inches (3.5 cm)
- Tufted Titmouse - 1 1/4 inches (3.2 cm)
- Violet-Green Swallow - 1 1/2 inches (3.8 cm)
- Western Screech-Owl - 3 inches (7.6 cm)
- White-Breasted Nuthatch - 1 1/4 inches (3.2 cm)
- Wood Duck - 4 inches (10.2 cm)